What is the cheapest airline that flies from Portland to London Heathrow?

American Airlines, KLM, and United Airlines are the most popular carriers operating from Portland to London Heathrow

What airlines fly to London Heathrow Airport?

British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to London Heathrow Airport from Portland, Maine according to our data. British Airways is the first choice among our users, with 47% of people opting to fly with this airline when traveling to London Heathrow Airport. Keep in mind that there are 16 different airlines that fly to London Heathrow Airport on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Portland Airport to London Heathrow Airport?

Prices for flights from Portland Airport to London Heathrow Airport refresh daily.

How many operators does momondo search for flights from Portland Airport to London Heathrow Airport?

There is 1 operator available for flights from Portland Airport to London Heathrow Airport as of October 2026.

How old do you have to be to fly from Portland Airport to London Heathrow Airport?

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London Heathrow Airport.

What documentation or ID do you need to fly to London Heathrow Airport?

The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

$290 Cheap Flights from Portland, Maine to London Heathrow Airport in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Portland, Maine to London

Round-trip

One-way

Cheap round-trip flights

Enter your travel dates to find the best prices.

3:41 pm - 4:20 pmPWM Portland-LHR London Heathrow

19h 39m2 stops Newark Zurich

9:00 am - 11:21 pmLHR London Heathrow-PWM Portland

43h 21m2 stops Halifax Intl Newark

$765United Airlines

Mon, Nov 16 - Wed, Nov 18

3:41 pm - 11:15 amPWM Portland-LHR London Heathrow

14h 34m2 stops Newark Zurich

9:00 am - 11:21 pmLHR London Heathrow-PWM Portland

43h 21m2 stops Halifax Intl Newark

$766United Airlines

Mon, Nov 16 - Wed, Nov 18

3:41 pm - 9:10 amPWM Portland-LHR London Heathrow

12h 29m1 stop Newark

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$767United Airlines

Mon, Nov 16 - Wed, Nov 18

5:50 am - 9:20 pmPWM Portland-LHR London Heathrow

10h 30m1 stop Newark

9:00 am - 11:21 pmLHR London Heathrow-PWM Portland

19h 21m2 stops Zurich Newark

$767United Airlines

Tue, Nov 10 - Wed, Nov 11

8:49 am - 9:10 amPWM Portland-LHR London Heathrow

19h 21m1 stop Newark

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$767United Airlines

Mon, Nov 16 - Wed, Nov 18

9:46 am - 10:50 amPWM Portland-LHR London Heathrow

20h 04m1 stop Washington, D.C. Dulles Intl

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$767United Airlines

Tue, Nov 10 - Thu, Nov 12

9:46 am - 10:50 amPWM Portland-LHR London Heathrow

20h 04m1 stop Washington, D.C. Dulles Intl

9:00 am - 11:21 pmLHR London Heathrow-PWM Portland

19h 21m2 stops Zurich Newark

$767United Airlines

Tue, Nov 10 - Thu, Nov 12

9:46 am - 7:10 amPWM Portland-LHR London Heathrow

16h 24m2 stops Washington, D.C. Dulles Intl Montreal Pierre Elliott Trudeau Intl

6:00 am - 11:21 pmLHR London Heathrow-PWM Portland

22h 21m3 stops Zurich Toronto Pearson Intl Newark

$778Multiple Airlines

Tue, Nov 10 - Thu, Nov 12

8:49 am - 6:30 amPWM Portland-LHR London Heathrow

16h 41m3 stops Newark Montreal Pierre Elliott Trudeau Intl Toronto Pearson Intl

6:00 am - 11:21 pmLHR London Heathrow-PWM Portland

22h 21m3 stops Zurich Toronto Pearson Intl Newark

$786Air Canada

Tue, Nov 10 - Thu, Nov 12

8:49 am - 7:10 amPWM Portland-LHR London Heathrow

17h 21m3 stops Newark Toronto Pearson Intl Montreal Pierre Elliott Trudeau Intl

6:00 am - 11:21 pmLHR London Heathrow-PWM Portland

22h 21m3 stops Zurich Toronto Pearson Intl Newark

$786Air Canada

Tue, Nov 10 - Thu, Nov 12

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United Airlines flights from Portland, Maine to London Heathrow Airport

Our best United Airlines deals on Portland, Maine to London Heathrow Airport flight tickets

United Airlines

Nov 16

PWM3:41 pmPortland

19h 39m

2 stops

LHR4:20 pmLondon Heathrow

Nov 18

LHR9:00 amLondon Heathrow

43h 21m

2 stops

PWM11:21 pmPortland

$765

United Airlines

Nov 16

PWM3:41 pmPortland

14h 34m

2 stops

LHR11:15 amLondon Heathrow

Nov 18

LHR9:00 amLondon Heathrow

43h 21m

2 stops

PWM11:21 pmPortland

$766

United Airlines

Nov 16

PWM3:41 pmPortland

12h 29m

1 stop

LHR9:10 amLondon Heathrow

Nov 18

LHR6:50 amLondon Heathrow

21h 31m

2 stops

PWM11:21 pmPortland

$767

Delta flights from Portland, Maine to London Heathrow Airport

Our best Delta deals on Portland, Maine to London Heathrow Airport flight tickets

Delta

Nov 7

PWM1:10 pmPortland

13h 35m

1 stop

LHR7:45 amLondon Heathrow

Nov 14

LHR6:30 amLondon Heathrow

22h 49m

2 stops

PWM12:19 amPortland

$866

Delta

Nov 7

PWM2:33 pmPortland

18h 12m

2 stops

LHR1:45 pmLondon Heathrow

Nov 14

LHR6:30 amLondon Heathrow

22h 49m

2 stops

PWM12:19 amPortland

$870

Delta

Dec 6

PWM4:00 pmPortland

13h 30m

1 stop

LHR10:30 amLondon Heathrow

Dec 13

LHR8:40 amLondon Heathrow

20h 41m

2 stops

PWM12:21 amPortland

$876

momondo Fare Finder

Use the filters below to find and compare flights from Portland, Maine to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/16

3:41 pm-4:20 pm

2 stops19h 39m

London Heathrow

Wed 11/18

9:00 am-11:21 pm

2 stops43h 21m

$765

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/16

3:41 pm-11:15 am

2 stops14h 34m

London Heathrow

Wed 11/18

9:00 am-11:21 pm

2 stops43h 21m

$766

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/16

3:41 pm-9:10 am

1 stop12h 29m

London Heathrow

Wed 11/18

6:50 am-11:21 pm

2 stops21h 31m

$767

Quickest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

5:50 am-9:20 pm

1 stop10h 30m

London Heathrow

Wed 11/11

9:00 am-11:21 pm

2 stops19h 21m

$767

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/16

8:49 am-9:10 am

1 stop19h 21m

London Heathrow

Wed 11/18

6:50 am-11:21 pm

2 stops21h 31m

$767

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

9:46 am-10:50 am

1 stop20h 04m

London Heathrow

Thu 11/12

6:50 am-11:21 pm

2 stops21h 31m

$767

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

9:46 am-10:50 am

1 stop20h 04m

London Heathrow

Thu 11/12

9:00 am-11:21 pm

2 stops19h 21m

$767

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

9:46 am-7:10 am

2 stops16h 24m

London Heathrow

Thu 11/12

6:00 am-11:21 pm

3 stops22h 21m

$778

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

8:49 am-6:30 am

3 stops16h 41m

London Heathrow

Thu 11/12

6:00 am-11:21 pm

3 stops22h 21m

$786

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

8:49 am-7:10 am

3 stops17h 21m

London Heathrow

Thu 11/12

6:00 am-11:21 pm

3 stops22h 21m

$786

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Portland, Maine to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

Prices

Airlines

What is the cheapest month to fly to London Heathrow Airport?

The month of January is, on average, the cheapest month to fly to London Heathrow Airport from Portland, Maine, with most prices found around $0. If you’re not able to fly to London Heathrow Airport in January, then March is your next best option. Flight prices from Portland, Maine to London Heathrow Airport during March average around $654.

When to book flights from Portland, Maine to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Portland, Maine to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap Portland, Maine to London Heathrow Airport (PWM to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Portland, Maine to London Heathrow Airport

Best Price Found	$290
Fastest flight time	11h 05m
Direct flights	None

The best one-way flight to London Heathrow Airport from Portland, Maine in the past 72 hours is $290. The best round-trip flight deal from Portland, Maine to London Heathrow Airport found on momondo in the last 72 hours is $765.

The fastest flight from Portland, Maine to London Heathrow Airport takes 11h 05m

There are no direct flights from Portland, Maine to London Heathrow Airport. There are no popular flight routes from Portland, Maine to London Heathrow Airport.

Search flight deals

Frequently asked questions about flying from Portland, Maine to London Heathrow Airport

How far is Portland to London Heathrow by plane?
The distance between Portland and London Heathrow is about 3170.3 mi. In terms of flight time, this usually takes a little over 11h 05m.
When did momondo last update prices for flights from Portland Airport to London Heathrow Airport?
Prices for flights from Portland Airport to London Heathrow Airport refresh daily.
How many operators does momondo search for flights from Portland Airport to London Heathrow Airport?
There is 1 operator available for flights from Portland Airport to London Heathrow Airport as of October 2026.
How old do you have to be to fly from Portland Airport to London Heathrow Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London Heathrow Airport.
What documentation or ID do you need to fly to London Heathrow Airport?
The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular airline from Portland, Maine to London Heathrow Airport?
Based on momondo bookings for flights between Portland, Maine and London Heathrow Airport, the leading airline is United Airlines, making up 100% of the total bookings.

Best airlines flying from Portland, Maine to London Heathrow Airport

Compare and see reviews for airlines that fly from Portland, Maine to London Heathrow Airport with momondo

Airline	Rating	Free Cancellation	Price
United Airlines	PriceFrom $752	Free Cancellation	Rating 7.3 10,440 reviews		Search United Airlines flights

Hounslow

Gatwick

Croydon

Hayes

Milton Keynes

Luton

Stansted

Kingston upon Thames

Dover

Wembley

Stratford-upon-Avon

Richmond

Watford

Crawley

Worthing

Harrow

Slough

Hook

Ilford

Canterbury

Why use momondo?

Why should I use momondo to find a flight deal from Portland to London?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to London from Portland.

Can I find flights from Portland to London with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to London from Portland with this policy.

How can momondo help me find flights from Portland to London?

Once you have performed a search for Portland to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Portland to London right now. Can momondo alert me if prices change?

If you are simply researching potential flights to London, momondo offers a useful price alert feature which will track prices for flights to London from Portland and alert you when they change.

An easier way to manage your London Heathrow Airport trip

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Cheap flights from Portland, Maine to London from $290

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland, Maine to London departing on 11/17. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Find the cheapest flights from Portland, Maine to London

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United Airlines flights from Portland, Maine to London Heathrow Airport

Our best United Airlines deals on Portland, Maine to London Heathrow Airport flight tickets

Delta flights from Portland, Maine to London Heathrow Airport

Our best Delta deals on Portland, Maine to London Heathrow Airport flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Portland, Maine to London Heathrow Airport that are best for you.

See travel insights to London from

How to get the cheapest flight ticket from Portland, Maine to London Heathrow Airport

What is the cheapest month to fly to London Heathrow Airport?

What is the cheapest airline that flies from Portland to London Heathrow?

What airlines fly to London Heathrow Airport?

When to book flights from Portland, Maine to London Heathrow Airport

Cheap Portland, Maine to London Heathrow Airport (PWM to LHR) flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Frequently asked questions about flying from Portland, Maine to London Heathrow Airport

Best airlines flying from Portland, Maine to London Heathrow Airport

Compare and see reviews for airlines that fly from Portland, Maine to London Heathrow Airport with momondo

Traveling to a place near London?

Why use momondo?

An easier way to manage your London Heathrow Airport trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to London

Popular cities in the United Kingdom

Popular flights according to clicks in the last 7 days on momondo

Portland, Maine flight routes

According to popular flight searches on momondo this year

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List of cabin classes available on flights landing in London. Availability may vary depending on flight origin and airline.

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